1. Technical Field
This invention relates generally to high pressure water or air systems and more particularly to a dump valve operative to immediately substantially reduce or eliminate pressurized flow at the outlet to prevent damage or injury without shutting down the source of pressurized fluid.
2. Description of the Prior Art
In any fluid system including a high pressure pump, it may be difficult or impossible to immediately depressurize the system to avoid damage or injury. In a water blasting concrete removal machine, for example, where one or more high pressure water nozzles are strategically moved in a pattern across a concrete surface to remove a predetermined depth of concrete, it may be critical to immediately cut the pressure in the system. This may be necessary to avoid damage upon encountering unexpectedly weak concrete or upon the machine advancing out of the targeted area needing repair. Likewise, pressure would have to be immediately cut upon a person slipping and falling into the path of the machine, for example. In other types of high pressure systems, other emergencies such as a blast of fluid from an accidental leak may require that system pressure be immediately cut off.
One solution is to deactivate the high pressure pump, but that would not likely provide immediate pressure relief. Furthermore, in industrial settings, such shutdown of the high pressure pump can result in significant downtime and lost production.
Another solution is to provide a dump valve through which system pressure can be exhausted. Known dump valves for high pressure water or air systems have shortcomings which limit their effectiveness, however. Many include O-rings or gaskets which deteriorate over time and with use. Such valves require regular maintenance to avoid leakage or failure. Other dump valves have to be manually opened and therefore require undue time for accessing the valve and manually opening it.
Accordingly, a primary object of the invention is to provide an improved dump valve for a high pressure fluid system.
Another object is to provide a dump valve which may be remotely operated for immediate opening of the valve.
Another object is to provide a dump valve which includes no O-rings or gaskets.
Another object is to provide a dump valve which is operative to immediately cut system pressure without shutting down the high pressure pump, thereby enabling quick system restoration once the emergency condition has been resolved.
Another object is to provide a dump valve which requires no regular maintenance and which has no parts requiring replacement.
Finally, an object of the invention is to provide a dump valve which is simple and rugged in construction, economical to manufacture and efficient in operation.
The dump valve of the present invention includes a base and a fitting secured to the base and adapted to be interposed along a high pressure fluid line. The fitting defines an internal manifold having an inlet and an outlet adapted for connection to the high pressure fluid line for flow of high pressure fluid through the manifold. The fitting further includes a dump port in fluid communication with the manifold. A valve seat is arranged within the dump port and has an opening in fluid communication with the manifold. An extendable and retractable fluid cylinder is mounted on the base in spaced relation from the fitting and has a valve member mounted thereon for movement between a valve closed position in engagement with the valve seat, closing the opening in the dump port, and a valve open position in spaced relation from the valve seat whereby high pressure fluid in the manifold is ejected from the dump port upon movement of the valve member to the valve open position.
The dump valve of the invention may be used in high pressure water or air systems. Likewise, the extendable and retractable fluid cylinder may be hydraulic or pneumatic. That fluid cylinder applies a continuous force to hold the valve member in the valve closed position against the urging of high pressure fluid in the manifold.
In one embodiment, a female valve seat within the dump port has a frustoconical valve surface which flares outwardly toward the male valve member which has a frustoconical valve surface that tapers toward the valve seat.
The dump valve of the invention can be made in sizes ranging from tiny to large to accommodate flows as little as one half gallon per minute at five hundred pounds per square inch, for example, to flows as much as one thousand or more gallons per minute and pressures on the order of twenty thousand pounds per square inch. The valve seats may be of any size to accommodate a given system and the fluid cylinders likewise may be of any size to maintain the valve closed against the system pressure.